firmware-utils: honor env SOURCE_DATE_EPOCH

Use the timestamp from the enviroment SOURCE_DATE_EPOCH
if set instead of the build time.
Fixes reproducible builds for certain firmware images.

Signed-off-by: Alexander Couzens <lynxis@fe80.eu>

1 files changed, 19 insertions, 1 deletions

diff --git a/tools/firmware-utils/src/addpattern.c b/tools/firmware-utils/src/addpattern.c
index 2ecc7ffd75..9bc4865335 100644
--- a/tools/firmware-utils/src/addpattern.c
+++ b/tools/firmware-utils/src/addpattern.c
@@ -58,6 +58,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/stat.h>
@@ -141,6 +142,20 @@ void usage(void)
 	exit(EXIT_FAILURE);
 }
 
+static time_t source_date_epoch = -1;
+static void set_source_date_epoch() {
+	char *env = getenv("SOURCE_DATE_EPOCH");
+	char *endptr = env;
+	errno = 0;
+        if (env && *env) {
+		source_date_epoch = strtoull(env, &endptr, 10);
+		if (errno || (endptr && *endptr != '\0')) {
+			fprintf(stderr, "Invalid SOURCE_DATE_EPOCH");
+			exit(1);
+		}
+        }
+}
+
 struct board_info *find_board(char *id)
 {
 	struct board_info *board;
@@ -273,7 +288,10 @@ int main(int argc, char **argv)
 		usage();
 	}
 
-	if (time(&t) == (time_t)(-1)) {
+	set_source_date_epoch();
+	if (source_date_epoch != -1) {
+		t = source_date_epoch;
+	} else if ((time(&t) == (time_t)(-1))) {
 		fprintf(stderr, "time call failed\n");
 		return EXIT_FAILURE;
 	}